| Info | Votes | Messages | More Stats |
 Up One Level
|
 | ||||
Subject: Re: vote by edz By: Anonymous (xxx.xxx.43.173) In Reply to: edz (Original Vote) Date: 07/02/2008 07:01:44 am PST Thank you so much for the detail and effort which you put into the review. I own an early pair of Oberwerk 20x80's and love them, but, I am thinking about the 22x100's. You review made up my mind, and, also helped me understand the issues which I had seen in my 20x80's. I had collimated my 20x80's and they have held the collimation as you mention later. Dan >Oberwerk Giant 22x100 compared to Celestron Skymaster 25x100 > >I had several months to use these binoculars. As far as the ability to see, 22x100s and 25x100s are a step above every 20x80 or smaller binocs I've used. Literally, they see more. They see fainter objects, and image scale is larger. > >These binoculars are not perfect. I’ve seen slight flares in the image; I’ve seen a slightly bloated image in one or both sides of the binocular. Even with those deficiencies, these are the results achieved over a long period of months of use. What is most noticed is the dramatic increases in what can be seen with larger binoculars. > > >These are big, real big. And they show it. They require a substantial mount, not just any tripod but a heavy-duty tripod with a heavy-duty head. These binocs weigh about 8-10#. The best mount I have used for both of these binoculars is a sturdy Bogen 3246 tripod with a heavy duty Bogen 501 head. That setup will easily hold either of these 100mm binoculars. > >The Oberwerk 22x100 has a black metal base plate which screws onto the bottom of the mount post. This makes a 1.5" diameter bottom contact area with the tripod mounting plate. It spreads out the area of connection to the tripod plate, eliminates the punching deformation of the rubber on the quick release shoe and it never once got loose. > > >In my sample of the Oberwerk 22x100, The best image sharpness is not centered in the lens. In order to see it, sharpness needs to be tested across the lens at various hour lines on a clock. Then it becomes obvious. Along one hour line, sharpness is OK to 70%, poor by 80%. But on the opposite side, it's sharp to only 40-50% and poor by 60%. Testing other hour lines shows the sharp central point is off-axis. > >When observing a 14" double, the Celestron 25x100 was very clear at 50%, still good at 60% but poor at 70%, all the way around. Same double in the Obie 22x100, on one side was good to 60-70% and poor at 80%, but on the opposite side of the same barrel was good to only 40% out and poor by 50-60% out. > > >Looking at light reflected inside the Oberwerk 22x100 shows a green reflection off the prism face towards the objective. The same in the Celestron 25x100 shows a light blue reflection off the prism face. Both had objective coatings that appeared purple/green with very little reflection off the objective lens. > > >Under my best skies ranging from mag 5.4 to 5.8, >20x80 Oberwerk Standard see stars to a limit of mag 11.2, >22x100 Oberwerk is capable of seeing stars as faint as 11.8, >25x100 Celestron could reach nearly to stars at mag 12.0. > >I tried Mesartim with the Oberwerk 22x100. I saw a clean split. Difficult, but clean. Two nice little points with the tiniest of black space between them. > >That’s the best I could do with the 22x100s. 7.8†for an apparent separation of 7.8x22 = 172 arcseconds. With the 25x100s I got 7.1†for an apparent separation of 178 arcseconds. With Fujinon 16x70, I have seen Gamma Delphinus 9.6†split at 16x for an apparent separation of 154 arcseconds. > > >The Celestron Skymaster 25x100 binocular is advertised as 3.0°. It measures 2.45°. >The Oberwerk 22x100 is advertised as 2.8°. It actually measures Tfov at 2.7°. >They are still stamped on the prism housing as 3.5°, an artifact I presume left over from the fact that these binoculars use the older 20x80 Deluxe housing. > > >In the Oberwerk 22x100, Jupiter on-axis has very little CA, off-axis has moderate blue to one side. CA on the moon was a thin band and it was easy to move my eye placement to make it go away. With Jupiter at the very edge of the FOV in the 22x100s, CA is a pronounced red/ purple on the side towards the center of the lens. > >In the Celestron 25x100, Saturn produced no CA at all. None Seen in Venus on-axis, but blue and sometimes a purple or green was seen off-axis. Very little CA is seen on Jupiter out to about 50-60% from center. Beyond that, Jupiter produces blue CA on the inside edge and yellow/green on the outer edge. Ca on the moon was green towards the outer edge. > > >M101 was found instantly in the 25x100, it was seen equally well in the 22x100, but on the same night it was only suspected in the 16x70s. > >In the area just south of M11, oc M26 is seen easy in the 16x70 Fujinon, but nearby gc 6712 and oc 6664 are not seen at all. In 20x80 Oberwerk Standards, 6712 is seen and in 6664 only 3 or 4 stars can be glimpsed. In both the 22x100s and 25x100s, 6712 is seen readily and 8-10 stars can be counted directly in 6664. > >The Pleiades is just a little too large to be viewed in context, but the amazing depth provided by the 22x100 and 25x100 binocs allows seeing about 200 stars in this cluster. > >When you view faint clusters in 25x100s you see stars that just were not there in any smaller binocular. Star counts on clusters like IC4665 in Ophiuchus show 51* in the 25x100, 50* in the 22x100, but only 40* in the 16x70. > > >Light is off-center in both objectives. Light from the center of the objective does not produce the maximum exit pupil. Light at 70% out on the objective radius, on one side of center, illuminates 80% of the exit pupil. With the light source on the opposite side of center, no point in the exit pupil is fully illuminated and the central 20% diameter of the exit pupil gets no light at all. On average, the central 40% of the exit pupil receives no light at all from the outer edge of the objective. This off-center illumination is, in my opinion, a substantial reason to consider this sample unacceptable. However, at this time I know of possibly only a handful of people besides myself who would ever perform such a test to find this anomaly. Maybe this is a good case for “ignorance is blissâ€, because I was still able to see an awful lot of good stuff with both these binoculars. > > >The Oberwerk 22x100 uses the body from the older model 20x80 Deluxe. Instead of dew shields screwed onto the front end, the extension is now part of the binocular body and the objective lens is moved out about 3†further. The 22x100, just like the old discontinued 20x80 Deluxe has a right diopter adjustment that seems set incorrectly at the factory. I use my corrective glasses with all my binoculars. Therefore, with many binoculars, the right eye diopter is set on or near zero. With the 22x100, it is almost at the very end of the minus diopter range. Like the older 20x80 deluxe, I could not use these binoculars without my glasses if I wanted to. > > >I've put three different pair of 100mm binoculars up against the 16x70 Fujinons and Oberwerk 20x80s. The fact is, even with each of the 100mm binoculars with some optical deficiencies, the Fujinons could not see as much as any of the 100mm binoculars. In some cases it's like seeing it small in the 16x70s and then finally adding enough magnification to really see it. > >I have no doubt the Fujinon 16x70 reaches the finest pinpoint sharpness and resolution. I haven't found a binocular to beat it. None of these fixed power 80mm or 100mm binocular bring stars to as crisply defined focus as the Fujinons. The contrast in the Fujinons may be closely equaled, but not beaten. But, when it comes to how much can be seen, in just about every side-by-side viewing session, the larger binoculars saw more, and easily, not just barely. The 16x70s have a finer view, but the 22x100s and 25x100s will see more. If there are no optical deficiencies present that take away too much from the observation, even if you didn't add aperture, for most objects adding magnification allows you to see more. > >edz Page 1 of 1 | ||||||||
